In a multiple network environment deployed in a large field there is a need to manage the interference during the lifetime of the networks. This is because several communication protocols such as Wireless Highway Addressable Remote Transducer (WirelessHART) and WLAN work on the same Industrial, Scientific and Medical (ISM) frequency band, and sometimes in close vicinity, causing interference to each other.
Both WirelessHART and WLAN standard-based networks are deployed to operate on the same unlicensed radio frequency bands meant for industrial, scientific and medical (ISM) usage. When both these networks are operated in the same industrial plant or in the near vicinity to each other, then there is bound to be interferences between them. The effect of these interferences and the resulting performance degradation are well-known in the art.
In a WirelessHART network, the pseudo-random channel hopping feature ensures that the WirelessHART network is not fixed on a particular channel for any lengthy period of time. Thus this feature can eliminate the interference to a certain extent. However, problems occur when two or more packets of information are transmitted at the same time and frequency such that the packets “collide” in the same physical space. Even with careful system modeling and the deployment of the network, it is not always possible to limit the interferences over a life cycle period of the industrial plant; this could mainly be due to the change in topology of either of the network (addition or removal of the network elements) or with the change in the plant physical structure itself. Any pre-operation interference avoidance technique mainly considers only the historical interference information data for giving any necessary inputs to the planning and the engineering phase. Thus the dynamic changes in the network (topology, physical structure, priority to certain network elements) and the resulting interferences occurring during the operation phase cannot be adequately addressed. Accordingly, additional measures are required during the operational phase of the network so as to limit the effects of interference, from other interfering networks.